enhancer-data-bridge/database-proxy/pgsql.js

A bridge between Enhancer Clould and user business datasource

const { Pool, Client } = require('pg')

var dbTypeMap = {
    '23': 'integer',
    '1043': 'varchar',
    '1042': 'char',
    '1082': 'date',
    '1114': 'timestamp',
    '1700': 'numeric',
    '701': 'float',
    '790': 'money',
    '25': 'text',
    '1083': 'time'
};

var varTypeMap = {
    '23': 'number',
    '1043': 'string',
    '1042': 'string',
    '1082': 'date',
    '1114': 'date',
    '1700': 'number',
    '701': 'number',
    '790': 'number',
    '25': 'string',
    '1083': 'date'
};

module.exports = {
    testConnection: function(dbConfig, cb) {
        const client = new Client(dbConfig);
        client.connect();
        client.query('SELECT 1', function(err, result) {
            err ? cb(null, err.message) : cb(null, true);
            client.end();
        });
    },
    testSql: function(dbConfig, sql, params, cb) {
        // pgsql
        const client = new Client(dbConfig);
        client.connect();
        // limit
        sql = sql.replace(/\sLIMIT\s+(\d+|\?)\s*(\,\s*(\d+|\?)\s*)?$/i, '');
        sql = sql + ' LIMIT 1';

        // params placeholder
        var i = 1;
        sql = sql.replace(/\?/g, function(s) {
            return '$' + i++
        });

        client.query(sql, params, function(err, result) {
            if (err) {
                cb(null, {
                    success: false,
                    message: err.message
                });
                return client.end();
            }

            cb(null, {
                success: true,
                metaData: result.fields.map(function(f) {
                    f.dbType = dbTypeMap[f.dataTypeID];
                    f.varType = varTypeMap[f.dataTypeID] || 'string';
                    return f;
                })
            });
            client.end();
        });
    }, 
    getTableNames: function(dbConfig, cb) {
        const client = new Client(dbConfig);
        client.connect();
        client.query('SELECT table_name FROM information_schema.tables WHERE table_schema = \'public\''
            , [], function(err, result) {
            if ( err ) {
                cb(err);
                return client.end();
            }
            var tableNames = [];
            for (var i in result.rows) {
                tableNames.push(result.rows[i].table_name);
            }
            cb(null, tableNames);
            client.end();
        });
    },
    getTableColumns: function(dbConfig, tabName, cb) {
        const client = new Client(dbConfig);
        client.connect();
        client.query('SELECT * FROM information_schema.columns WHERE table_name = $1'
            , [tabName], function(err, result) {
            if ( err ) {
                cb(err);
                return client.end();
            }
            var columns = result.rows.map(function(col) {
                col.name = col.column_name;
                col.dbType = col.data_type;
                return col;
            });
            cb(null, columns);
            client.end();
        });
    }
}